题目黑体20磅段前22磅段后18磅.doc

题目黑体20磅段前22磅段后18磅 作者1，作者2楷体12.5磅段后4磅 (作者单位 二级单位, 省 市，邮编)宋体小5号段后15磅 摘 要黑体小5号: 宋体小5号空间矢量调制(SVPWM)是三相PWM整流器中是应用最广泛的控制方法。本文针对在同步旋转坐标系中采用电流解耦控制的PWM整流器, 建立了基于SVPWM的三相PWM整流器的Matlab/Simulink模型, SVPWM采用相邻的离散矢量跟踪连续变化的参考矢量, 其跟踪过程只对矢量作用时间有限制而对矢量的组合顺序没有要求。分析结果表明三相SVPWM调制的交流侧具有良好的电流波形品质, 且无功分量低, 而两相SVPWM调制具有开关次数少, 动态响应快, 适合于大功率整流场合应用。 关键词Vector Pulse Width Modulation (SVPWM)新罗马体4号 WANG Chongwu, LI Hong (College of Marine Engineering, Northwestern Ploytechnical University, Xi’an 710072, China) Abstract: Space vector pulse width modulations are the most wildly used methods in three phase PWM rectifiers because of the simple configuration and fixed switching frequency. In this paper a three phases PWM rectifier was set up using Matlab/Simulink in the synchronous d?q coordination. The SVPWM utilizes adjacent discrete vectors to track the continuous reference vector, and in the tracking process there is only constrain to the vectors working time other than the vectors sequence in one period. The several vector sequence patterns were investigated to study the influence on the THD and power factor-PF of the AC side, and the results reveal that the three phases modulating methods have good wave quality and low reactive power, the two phases modulations have low switching frequency and fast response and suit for the application in large rat power rectifiers. Key words: PWM rectifiers, SVPWM, current decoupled control, THD. 0 引言黑体小4号 宋体10磅，字体加宽0.2磅，多倍行距1.08在AC/DC变换器中, 不控整流或相控整流引起的电网电压波形畸变, 导致交流侧的功率因数低, 向电网注入大量的谐波电流, 造成电网的谐波污染[1-4]。三相PWM整流器具有功率因数高, 输入电流为正弦的特点, 是理想的AC/DC变换器方案。而目前AC/DC控制方案中, 电流控制方式是最重要的控制方法, 这主要因为电流控制准 确性高, 动态相应快, 对负载参数变换具有补偿功能等优点[4]。常用的电流控制方案是强迫交流侧的电流跟踪正弦参考信号, 用反馈电流和给定电流信号的误差信号, 通过调节器产生整流桥的 开关信号, 因此电流控制器的主要功能是电流误差的补偿和调制。文献[1]和[3]所示的方案都采用了电流滞环来实现PWM调制, 实际控制时由于滞环宽度导致开关频率不固定, 对功率器件的吸收、驱动参数设计带来困难, 并且导致整流器运行噪声增加, 产生电磁干扰问题[4]。 图1 整流器拓扑结构黑体8.5磅 Fig. 1 three phases新罗马体加粗8.5磅 1 功率因数控制原理 对图1所示的三相PWM整流器, ua, ub, uc为发电机的感应电势, L, R为每一相绕组的漏感和电阻, uca, ucb, ucc为三相桥的中点电压, 对六个开